An American Commercial Lines barge was being loaded when about 2,500 gallons of crude oil and natural gas condensate spilled. The barge was in a turn lane, just off the main river, so the oil didn't flow into the main river, Kendrick said.

Coast Guard officials are investigating the incident, but it is thought that an overflow valve malfunctioned, causing the spill, Kendrick said.

The spill was stopped by about 7:30 p.m. and crews have been working since to clean up the oil. Officials from Texas Parks and Wildlife, the Texas General Land Office and the Coast Guard responded to the spill.

As of Friday evening, the Coast Guard and four commercial response crews were still at work cleaning the spill with about 200 gallons left to be removed from the water.

Because of favorable weather conditions and good response time, the spill had no environmental ramifications, Kendrick said.